U.S. Pat. No. 4,580,568, Gianturco shows a stainless steel stent made of zigzag loops of stainless steel wire. Such stents have come to be known as “Z-stents”. The delivery system for Gianturco includes a catheter with a tapered tip, fitted within a sheath.
EP-A-819 411 shows a self-expanding stent between a bed on an inner tube and a sleeve surface on an outer tube, release of the stent being effected by proximal withdrawal of the outer sleeve. The drawings show the distal end of the delivery system abrupt and flat. As described in EP-A-819 411, the event of deployment of the stent is followed by proximal withdrawal, from within the stent envelope, of the inner tube. In EP-A-819 411, the inner tube component of the delivery system, inside the stent envelope, has re-entrant surfaces associated with the bed in which the stent was originally confined. It is believed that any such re-entrant surfaces should be avoided, if at all possible.
U.S. Pat. No. 5,833,694 shows, in FIG. 20, a variation in which the delivery catheter has a uniform diameter and within it a pusher tube 22, the distal end 190 of which serves as a stop for the proximal end of the stent. To deploy the stent, the sheath is pulled back proximally while the distal end of the inner tube prevents proximal movement of the stent itself.
U.S. Pat. No. 5,782,855 Lau et al., shows a stent lying radially between an outer sheath and a balloon catheter. On the distal tip of the balloon catheter is a cone, into which is tucked a tapered distal tip of the outer sheath. For deployment of the stent, the sheath is withdrawn proximally with respect to the stent. After balloon expansion of the stent, the balloon catheter is withdrawn proximally so that the cone passes in the proximal direction the full length of the stent lumen. The cone has an exposed proximal-facing rim edge as it passes through the stent lumen.
U.S. Pat. No. 6,019,778 shows a delivery apparatus for a self-expanding shape memory alloy stent, which features a stent bed on an inner shaft and an outer sheath, which includes a braided reinforcing layer. There is a stop on the shaft member, proximal of the stent bed, to prevent proximal movement of the stent when the outer sheath is withdrawn proximally to release the stent. The braided reinforcement layer is preferably made from stainless steel and is stated to resist a tendency of the stent to become imbedded within the sheath, which surrounds it.
EP-A-720 837 shows an integrated double-function catheter system for balloon angioplasty and stent delivery. An outer sheath with a conically-shaped distal tip portion surrounds a stent. Radially inside the stent is a balloon catheter. The balloon is located well distal of the stent so as to allow better trackability of the distal end of the catheter over a flexible guide wire and through tortuous coronary arteries and through a long tight stenosis.
EP-A-554 579 shows a stent delivery device with coaxial shaft and sheath for a self-expanding stent. The sheath is provided at its distal tip with a protective tip, which is bonded to the sheath thermally or with adhesive, or can be made integral with the sheath. This tip is said to reduce the likelihood of injury to the bodily lumen wall during advancement of the catheter in the lumen.
EP-A-119 688 shows a process and apparatus for restoring patency to bodily vessels in which a shape memory alloy wire is contained within an outer sheath and is abutted at its proximal end by a pushing shaft. It is believed to be deployed by withdrawing the sheath proximally. The diameter of the sheath surrounding the prosthesis is very much greater than the diameter of the sheath for the remainder of its transluminal length, over which it is a relatively snug fit with the pushing shaft. The sheath is said to be inserted, as by conventional techniques, into the aorta of the patient, in order that the prosthesis can be placed at an aneurysm.
U.S. Pat. No. 4,665,918 shows an example of a delivery system for a self-expanding stent held within a surrounding sleeve, which is proximally withdrawn relative to a stent bed in a coaxial inner shaft, and with a tapered tip zone on the shaft, which protrudes beyond the distal end of the surrounding sleeve.
U.S. Pat. No. 5,662,703 shows a delivery device for a self-expanding stent, having an outer catheter surrounding an inner catheter and a tubular stent-retaining sheath formed of a rolling membrane. The self-expanding stent is located at the distal ends of the inner and outer catheters. The stent is radially inwardly constrained by a double-walled rollable membrane. The separate proximal ends of the radially inner and outer membrane portions are fixed respectively to inner and outer catheter components whereas the contiguous-distal ends of the membrane portions converge and narrow thereby to form a tapered tip. For stent release, the outer catheter is moved proximally at least twice the length of the stent in order to pull back proximally both the inner and outer layers of the membrane, thereby releasing the stent.
U.S. Pat. No. 5,735,859 shows a stent delivery device having an inner and outer catheter and a stent covered by a thin-walled sheath. The inner catheter projects beyond the distal end being fixed to the distal end of the outer catheter. The distal end of the sheath is releasably received in the distal section of the inner catheter distal to the stent. The sheath can be released from the distal section of the inner catheter and pulled back from the stent, thereby releasing said stent. Where the distal end of the sheath is received in the distal section of the inner catheter, a step in the radially outside surface of the inner catheter is present.
EP-A-747 022 shows a coil-reinforced retractable sleeve for a stent delivery catheter. One embodiment of the sleeve has a distal tip, which tapers inwardly and is provided with a plurality of slits, which extend proximally from the distal end of the sleeve and substantially parallel to the longitudinal axis of the sleeve, the slits functioning to provide the sleeve with a low profile adapted for traveling through a blood vessel.
EP-A-948 946 shows apparatus and methods for deployment and release of an intraluminal graft for treating a stenosis, the graft being surrounded by a cylindrical cover which is withdrawn proximally to release the graft. The cover can have an atraumatic distal end of reduced diameter in which there are slits extending axially from the distal end wall.
WO 99/49929 shows a rapid exchange delivery system to alleviate a stenosis in a body lumen, with the stent being covered by a retractable sheath, and the stent itself being mounted on a balloon. In the drawings, it appears that the diameter of the sheath is somewhat greater radially outside the stent than in a distal end zone of the sheath, distal of the stent, touching the underlying balloon.
EP-A-850 655 shows a catheter tip mold and cut process in which the molding process creates a flash which extends beyond the desired catheter tip, which flash is then parted from the distal end of the molded catheter tip by use of a cutter.
U.S. Pat. No. 5,843,090 shows an inner catheter with a step at its distal end when the outer catheter is withdrawn proximally. See FIG. 6
U.S. Pat. No. 5,743,874 also shows an inner catheter with a step in its outer surface. See FIG. 1, feature 81.
U.S. Pat. No. 6,726,712 shows a device 16 with a flexible outer catheter 18 with a marker 22 mounted to the catheter. The catheter has distal region 26 with two polymeric materials. A braid 34 is provided at one region of the catheter. The catheter has an outer layer, medial layer and a proximal outer layer which are bonded to a PTFE liner.
U.S. Pat. No. 4,898,591 shows a body 22 with an inner layer 30 and outer layer 32 with a reinforcing braid 34 disposed therebetween. The inner and outer layers 30 and 32 are formed from a blend, i.e., a mixture or intermingling of components, of Nylon and ester-linked polyether-polyamide copolymer in proportions selected to produce desired properties for the catheter.
U.S. Pat. No. 6,042,578 shows an intravascular catheter having an elongated tubular body formed with polymeric materials but no radio-opaque marker or filler due to the presence of a metallic reinforcing braiding.
U.S. Pat. Nos. 5,603,705 and 5,674,208 show an intravascular catheter with inner and outer tubular members provided with a support member formed from wire braiding.
U.S. Pat. Nos. 5,951,495 and 5,951,495 show the use of various adhesives to restrain the flaring of wire braiding in a catheter.
U.S. Pat. No. 6,212,422 shows a catheter with an inner member, outer member and a tubular braid layer therebetween. A braid restraint is also shown and described.
U.S. Pat. No. 6,505,066 shows a catheter with a lubricious liner and a wire braiding with adhesive means to restrain the free ends from flaring.
The documents described above are incorporated by reference herein in their entirety.